Emotion (2011)
A wife is sexually unsatisfied and takes on a lover. Her husband seeks the help of a sensual woman to aid them with their sexual problem.
Swinging
Friends with Benefits (2012)
Alex and Jessica pretend to be married to join a swinger’s club. Meanwhile, a husband in the club gets jealous because his wife is always screwing the same hot woman. From New Sensations
A Man and a Woman (1993)
A man evades a debt collector, so the debt collector sleeps in his house to wait for him and ends up screwing the man’s girlfriend.
Sex Games for Couples (1976) aka Fantaisies pour Couples – France
Two couples are cheating with each other’s spouses before having an official wife swap.
Official Wife Swap Parody (2010)
Couples exchange wives to live the other pair’s life, but unlike the tv show, swapping goes up to the bedroom.